xref: /openbmc/linux/fs/afs/rxrpc.c (revision 8e8d7f13b6d5a93b3d2cf9a4ceaaf923809fd5ac)
1 /* Maintain an RxRPC server socket to do AFS communications through
2  *
3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/slab.h>
13 #include <net/sock.h>
14 #include <net/af_rxrpc.h>
15 #include <rxrpc/packet.h>
16 #include "internal.h"
17 #include "afs_cm.h"
18 
19 struct socket *afs_socket; /* my RxRPC socket */
20 static struct workqueue_struct *afs_async_calls;
21 static struct afs_call *afs_spare_incoming_call;
22 static atomic_t afs_outstanding_calls;
23 
24 static void afs_free_call(struct afs_call *);
25 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
26 static int afs_wait_for_call_to_complete(struct afs_call *);
27 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
28 static int afs_dont_wait_for_call_to_complete(struct afs_call *);
29 static void afs_process_async_call(struct work_struct *);
30 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
31 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
32 static int afs_deliver_cm_op_id(struct afs_call *);
33 
34 /* synchronous call management */
35 const struct afs_wait_mode afs_sync_call = {
36 	.notify_rx	= afs_wake_up_call_waiter,
37 	.wait		= afs_wait_for_call_to_complete,
38 };
39 
40 /* asynchronous call management */
41 const struct afs_wait_mode afs_async_call = {
42 	.notify_rx	= afs_wake_up_async_call,
43 	.wait		= afs_dont_wait_for_call_to_complete,
44 };
45 
46 /* asynchronous incoming call management */
47 static const struct afs_wait_mode afs_async_incoming_call = {
48 	.notify_rx	= afs_wake_up_async_call,
49 };
50 
51 /* asynchronous incoming call initial processing */
52 static const struct afs_call_type afs_RXCMxxxx = {
53 	.name		= "CB.xxxx",
54 	.deliver	= afs_deliver_cm_op_id,
55 	.abort_to_error	= afs_abort_to_error,
56 };
57 
58 static void afs_charge_preallocation(struct work_struct *);
59 
60 static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
61 
62 static int afs_wait_atomic_t(atomic_t *p)
63 {
64 	schedule();
65 	return 0;
66 }
67 
68 /*
69  * open an RxRPC socket and bind it to be a server for callback notifications
70  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
71  */
72 int afs_open_socket(void)
73 {
74 	struct sockaddr_rxrpc srx;
75 	struct socket *socket;
76 	int ret;
77 
78 	_enter("");
79 
80 	ret = -ENOMEM;
81 	afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
82 	if (!afs_async_calls)
83 		goto error_0;
84 
85 	ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
86 	if (ret < 0)
87 		goto error_1;
88 
89 	socket->sk->sk_allocation = GFP_NOFS;
90 
91 	/* bind the callback manager's address to make this a server socket */
92 	srx.srx_family			= AF_RXRPC;
93 	srx.srx_service			= CM_SERVICE;
94 	srx.transport_type		= SOCK_DGRAM;
95 	srx.transport_len		= sizeof(srx.transport.sin);
96 	srx.transport.sin.sin_family	= AF_INET;
97 	srx.transport.sin.sin_port	= htons(AFS_CM_PORT);
98 	memset(&srx.transport.sin.sin_addr, 0,
99 	       sizeof(srx.transport.sin.sin_addr));
100 
101 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
102 	if (ret < 0)
103 		goto error_2;
104 
105 	rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
106 					   afs_rx_discard_new_call);
107 
108 	ret = kernel_listen(socket, INT_MAX);
109 	if (ret < 0)
110 		goto error_2;
111 
112 	afs_socket = socket;
113 	afs_charge_preallocation(NULL);
114 	_leave(" = 0");
115 	return 0;
116 
117 error_2:
118 	sock_release(socket);
119 error_1:
120 	destroy_workqueue(afs_async_calls);
121 error_0:
122 	_leave(" = %d", ret);
123 	return ret;
124 }
125 
126 /*
127  * close the RxRPC socket AFS was using
128  */
129 void afs_close_socket(void)
130 {
131 	_enter("");
132 
133 	if (afs_spare_incoming_call) {
134 		atomic_inc(&afs_outstanding_calls);
135 		afs_free_call(afs_spare_incoming_call);
136 		afs_spare_incoming_call = NULL;
137 	}
138 
139 	_debug("outstanding %u", atomic_read(&afs_outstanding_calls));
140 	wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
141 			 TASK_UNINTERRUPTIBLE);
142 	_debug("no outstanding calls");
143 
144 	flush_workqueue(afs_async_calls);
145 	kernel_sock_shutdown(afs_socket, SHUT_RDWR);
146 	flush_workqueue(afs_async_calls);
147 	sock_release(afs_socket);
148 
149 	_debug("dework");
150 	destroy_workqueue(afs_async_calls);
151 	_leave("");
152 }
153 
154 /*
155  * free a call
156  */
157 static void afs_free_call(struct afs_call *call)
158 {
159 	_debug("DONE %p{%s} [%d]",
160 	       call, call->type->name, atomic_read(&afs_outstanding_calls));
161 
162 	ASSERTCMP(call->rxcall, ==, NULL);
163 	ASSERT(!work_pending(&call->async_work));
164 	ASSERT(call->type->name != NULL);
165 
166 	kfree(call->request);
167 	kfree(call);
168 
169 	if (atomic_dec_and_test(&afs_outstanding_calls))
170 		wake_up_atomic_t(&afs_outstanding_calls);
171 }
172 
173 /*
174  * End a call but do not free it
175  */
176 static void afs_end_call_nofree(struct afs_call *call)
177 {
178 	if (call->rxcall) {
179 		rxrpc_kernel_end_call(afs_socket, call->rxcall);
180 		call->rxcall = NULL;
181 	}
182 	if (call->type->destructor)
183 		call->type->destructor(call);
184 }
185 
186 /*
187  * End a call and free it
188  */
189 static void afs_end_call(struct afs_call *call)
190 {
191 	afs_end_call_nofree(call);
192 	afs_free_call(call);
193 }
194 
195 /*
196  * allocate a call with flat request and reply buffers
197  */
198 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
199 				     size_t request_size, size_t reply_max)
200 {
201 	struct afs_call *call;
202 
203 	call = kzalloc(sizeof(*call), GFP_NOFS);
204 	if (!call)
205 		goto nomem_call;
206 
207 	_debug("CALL %p{%s} [%d]",
208 	       call, type->name, atomic_read(&afs_outstanding_calls));
209 	atomic_inc(&afs_outstanding_calls);
210 
211 	call->type = type;
212 	call->request_size = request_size;
213 	call->reply_max = reply_max;
214 
215 	if (request_size) {
216 		call->request = kmalloc(request_size, GFP_NOFS);
217 		if (!call->request)
218 			goto nomem_free;
219 	}
220 
221 	if (reply_max) {
222 		call->buffer = kmalloc(reply_max, GFP_NOFS);
223 		if (!call->buffer)
224 			goto nomem_free;
225 	}
226 
227 	init_waitqueue_head(&call->waitq);
228 	return call;
229 
230 nomem_free:
231 	afs_free_call(call);
232 nomem_call:
233 	return NULL;
234 }
235 
236 /*
237  * clean up a call with flat buffer
238  */
239 void afs_flat_call_destructor(struct afs_call *call)
240 {
241 	_enter("");
242 
243 	kfree(call->request);
244 	call->request = NULL;
245 	kfree(call->buffer);
246 	call->buffer = NULL;
247 }
248 
249 /*
250  * attach the data from a bunch of pages on an inode to a call
251  */
252 static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
253 			  struct kvec *iov)
254 {
255 	struct page *pages[8];
256 	unsigned count, n, loop, offset, to;
257 	pgoff_t first = call->first, last = call->last;
258 	int ret;
259 
260 	_enter("");
261 
262 	offset = call->first_offset;
263 	call->first_offset = 0;
264 
265 	do {
266 		_debug("attach %lx-%lx", first, last);
267 
268 		count = last - first + 1;
269 		if (count > ARRAY_SIZE(pages))
270 			count = ARRAY_SIZE(pages);
271 		n = find_get_pages_contig(call->mapping, first, count, pages);
272 		ASSERTCMP(n, ==, count);
273 
274 		loop = 0;
275 		do {
276 			msg->msg_flags = 0;
277 			to = PAGE_SIZE;
278 			if (first + loop >= last)
279 				to = call->last_to;
280 			else
281 				msg->msg_flags = MSG_MORE;
282 			iov->iov_base = kmap(pages[loop]) + offset;
283 			iov->iov_len = to - offset;
284 			offset = 0;
285 
286 			_debug("- range %u-%u%s",
287 			       offset, to, msg->msg_flags ? " [more]" : "");
288 			iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC,
289 				      iov, 1, to - offset);
290 
291 			/* have to change the state *before* sending the last
292 			 * packet as RxRPC might give us the reply before it
293 			 * returns from sending the request */
294 			if (first + loop >= last)
295 				call->state = AFS_CALL_AWAIT_REPLY;
296 			ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
297 						     msg, to - offset);
298 			kunmap(pages[loop]);
299 			if (ret < 0)
300 				break;
301 		} while (++loop < count);
302 		first += count;
303 
304 		for (loop = 0; loop < count; loop++)
305 			put_page(pages[loop]);
306 		if (ret < 0)
307 			break;
308 	} while (first <= last);
309 
310 	_leave(" = %d", ret);
311 	return ret;
312 }
313 
314 /*
315  * initiate a call
316  */
317 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
318 		  const struct afs_wait_mode *wait_mode)
319 {
320 	struct sockaddr_rxrpc srx;
321 	struct rxrpc_call *rxcall;
322 	struct msghdr msg;
323 	struct kvec iov[1];
324 	int ret;
325 
326 	_enter("%x,{%d},", addr->s_addr, ntohs(call->port));
327 
328 	ASSERT(call->type != NULL);
329 	ASSERT(call->type->name != NULL);
330 
331 	_debug("____MAKE %p{%s,%x} [%d]____",
332 	       call, call->type->name, key_serial(call->key),
333 	       atomic_read(&afs_outstanding_calls));
334 
335 	call->wait_mode = wait_mode;
336 	INIT_WORK(&call->async_work, afs_process_async_call);
337 
338 	memset(&srx, 0, sizeof(srx));
339 	srx.srx_family = AF_RXRPC;
340 	srx.srx_service = call->service_id;
341 	srx.transport_type = SOCK_DGRAM;
342 	srx.transport_len = sizeof(srx.transport.sin);
343 	srx.transport.sin.sin_family = AF_INET;
344 	srx.transport.sin.sin_port = call->port;
345 	memcpy(&srx.transport.sin.sin_addr, addr, 4);
346 
347 	/* create a call */
348 	rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
349 					 (unsigned long) call, gfp,
350 					 wait_mode->notify_rx);
351 	call->key = NULL;
352 	if (IS_ERR(rxcall)) {
353 		ret = PTR_ERR(rxcall);
354 		goto error_kill_call;
355 	}
356 
357 	call->rxcall = rxcall;
358 
359 	/* send the request */
360 	iov[0].iov_base	= call->request;
361 	iov[0].iov_len	= call->request_size;
362 
363 	msg.msg_name		= NULL;
364 	msg.msg_namelen		= 0;
365 	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
366 		      call->request_size);
367 	msg.msg_control		= NULL;
368 	msg.msg_controllen	= 0;
369 	msg.msg_flags		= (call->send_pages ? MSG_MORE : 0);
370 
371 	/* have to change the state *before* sending the last packet as RxRPC
372 	 * might give us the reply before it returns from sending the
373 	 * request */
374 	if (!call->send_pages)
375 		call->state = AFS_CALL_AWAIT_REPLY;
376 	ret = rxrpc_kernel_send_data(afs_socket, rxcall,
377 				     &msg, call->request_size);
378 	if (ret < 0)
379 		goto error_do_abort;
380 
381 	if (call->send_pages) {
382 		ret = afs_send_pages(call, &msg, iov);
383 		if (ret < 0)
384 			goto error_do_abort;
385 	}
386 
387 	/* at this point, an async call may no longer exist as it may have
388 	 * already completed */
389 	return wait_mode->wait(call);
390 
391 error_do_abort:
392 	rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT, -ret, "KSD");
393 error_kill_call:
394 	afs_end_call(call);
395 	_leave(" = %d", ret);
396 	return ret;
397 }
398 
399 /*
400  * deliver messages to a call
401  */
402 static void afs_deliver_to_call(struct afs_call *call)
403 {
404 	u32 abort_code;
405 	int ret;
406 
407 	_enter("%s", call->type->name);
408 
409 	while (call->state == AFS_CALL_AWAIT_REPLY ||
410 	       call->state == AFS_CALL_AWAIT_OP_ID ||
411 	       call->state == AFS_CALL_AWAIT_REQUEST ||
412 	       call->state == AFS_CALL_AWAIT_ACK
413 	       ) {
414 		if (call->state == AFS_CALL_AWAIT_ACK) {
415 			size_t offset = 0;
416 			ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
417 						     NULL, 0, &offset, false,
418 						     &call->abort_code);
419 			trace_afs_recv_data(call, 0, offset, false, ret);
420 
421 			if (ret == -EINPROGRESS || ret == -EAGAIN)
422 				return;
423 			if (ret == 1 || ret < 0) {
424 				call->state = AFS_CALL_COMPLETE;
425 				goto done;
426 			}
427 			return;
428 		}
429 
430 		ret = call->type->deliver(call);
431 		switch (ret) {
432 		case 0:
433 			if (call->state == AFS_CALL_AWAIT_REPLY)
434 				call->state = AFS_CALL_COMPLETE;
435 			goto done;
436 		case -EINPROGRESS:
437 		case -EAGAIN:
438 			goto out;
439 		case -ENOTCONN:
440 			abort_code = RX_CALL_DEAD;
441 			rxrpc_kernel_abort_call(afs_socket, call->rxcall,
442 						abort_code, -ret, "KNC");
443 			goto do_abort;
444 		case -ENOTSUPP:
445 			abort_code = RX_INVALID_OPERATION;
446 			rxrpc_kernel_abort_call(afs_socket, call->rxcall,
447 						abort_code, -ret, "KIV");
448 			goto do_abort;
449 		case -ENODATA:
450 		case -EBADMSG:
451 		case -EMSGSIZE:
452 		default:
453 			abort_code = RXGEN_CC_UNMARSHAL;
454 			if (call->state != AFS_CALL_AWAIT_REPLY)
455 				abort_code = RXGEN_SS_UNMARSHAL;
456 			rxrpc_kernel_abort_call(afs_socket, call->rxcall,
457 						abort_code, EBADMSG, "KUM");
458 			goto do_abort;
459 		}
460 	}
461 
462 done:
463 	if (call->state == AFS_CALL_COMPLETE && call->incoming)
464 		afs_end_call(call);
465 out:
466 	_leave("");
467 	return;
468 
469 do_abort:
470 	call->error = ret;
471 	call->state = AFS_CALL_COMPLETE;
472 	goto done;
473 }
474 
475 /*
476  * wait synchronously for a call to complete
477  */
478 static int afs_wait_for_call_to_complete(struct afs_call *call)
479 {
480 	const char *abort_why;
481 	int ret;
482 
483 	DECLARE_WAITQUEUE(myself, current);
484 
485 	_enter("");
486 
487 	add_wait_queue(&call->waitq, &myself);
488 	for (;;) {
489 		set_current_state(TASK_INTERRUPTIBLE);
490 
491 		/* deliver any messages that are in the queue */
492 		if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
493 			call->need_attention = false;
494 			__set_current_state(TASK_RUNNING);
495 			afs_deliver_to_call(call);
496 			continue;
497 		}
498 
499 		abort_why = "KWC";
500 		ret = call->error;
501 		if (call->state == AFS_CALL_COMPLETE)
502 			break;
503 		abort_why = "KWI";
504 		ret = -EINTR;
505 		if (signal_pending(current))
506 			break;
507 		schedule();
508 	}
509 
510 	remove_wait_queue(&call->waitq, &myself);
511 	__set_current_state(TASK_RUNNING);
512 
513 	/* kill the call */
514 	if (call->state < AFS_CALL_COMPLETE) {
515 		_debug("call incomplete");
516 		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
517 					RX_CALL_DEAD, -ret, abort_why);
518 	}
519 
520 	_debug("call complete");
521 	afs_end_call(call);
522 	_leave(" = %d", ret);
523 	return ret;
524 }
525 
526 /*
527  * wake up a waiting call
528  */
529 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
530 				    unsigned long call_user_ID)
531 {
532 	struct afs_call *call = (struct afs_call *)call_user_ID;
533 
534 	call->need_attention = true;
535 	wake_up(&call->waitq);
536 }
537 
538 /*
539  * wake up an asynchronous call
540  */
541 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
542 				   unsigned long call_user_ID)
543 {
544 	struct afs_call *call = (struct afs_call *)call_user_ID;
545 
546 	trace_afs_notify_call(rxcall, call);
547 	call->need_attention = true;
548 	queue_work(afs_async_calls, &call->async_work);
549 }
550 
551 /*
552  * put a call into asynchronous mode
553  * - mustn't touch the call descriptor as the call my have completed by the
554  *   time we get here
555  */
556 static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
557 {
558 	_enter("");
559 	return -EINPROGRESS;
560 }
561 
562 /*
563  * delete an asynchronous call
564  */
565 static void afs_delete_async_call(struct work_struct *work)
566 {
567 	struct afs_call *call = container_of(work, struct afs_call, async_work);
568 
569 	_enter("");
570 
571 	afs_free_call(call);
572 
573 	_leave("");
574 }
575 
576 /*
577  * perform processing on an asynchronous call
578  */
579 static void afs_process_async_call(struct work_struct *work)
580 {
581 	struct afs_call *call = container_of(work, struct afs_call, async_work);
582 
583 	_enter("");
584 
585 	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
586 		call->need_attention = false;
587 		afs_deliver_to_call(call);
588 	}
589 
590 	if (call->state == AFS_CALL_COMPLETE && call->wait_mode) {
591 		if (call->wait_mode->async_complete)
592 			call->wait_mode->async_complete(call->reply,
593 							call->error);
594 		call->reply = NULL;
595 
596 		/* kill the call */
597 		afs_end_call_nofree(call);
598 
599 		/* we can't just delete the call because the work item may be
600 		 * queued */
601 		call->async_work.func = afs_delete_async_call;
602 		queue_work(afs_async_calls, &call->async_work);
603 	}
604 
605 	_leave("");
606 }
607 
608 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
609 {
610 	struct afs_call *call = (struct afs_call *)user_call_ID;
611 
612 	call->rxcall = rxcall;
613 }
614 
615 /*
616  * Charge the incoming call preallocation.
617  */
618 static void afs_charge_preallocation(struct work_struct *work)
619 {
620 	struct afs_call *call = afs_spare_incoming_call;
621 
622 	for (;;) {
623 		if (!call) {
624 			call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
625 			if (!call)
626 				break;
627 
628 			INIT_WORK(&call->async_work, afs_process_async_call);
629 			call->wait_mode = &afs_async_incoming_call;
630 			call->type = &afs_RXCMxxxx;
631 			init_waitqueue_head(&call->waitq);
632 			call->state = AFS_CALL_AWAIT_OP_ID;
633 		}
634 
635 		if (rxrpc_kernel_charge_accept(afs_socket,
636 					       afs_wake_up_async_call,
637 					       afs_rx_attach,
638 					       (unsigned long)call,
639 					       GFP_KERNEL) < 0)
640 			break;
641 		call = NULL;
642 	}
643 	afs_spare_incoming_call = call;
644 }
645 
646 /*
647  * Discard a preallocated call when a socket is shut down.
648  */
649 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
650 				    unsigned long user_call_ID)
651 {
652 	struct afs_call *call = (struct afs_call *)user_call_ID;
653 
654 	atomic_inc(&afs_outstanding_calls);
655 	call->rxcall = NULL;
656 	afs_free_call(call);
657 }
658 
659 /*
660  * Notification of an incoming call.
661  */
662 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
663 			    unsigned long user_call_ID)
664 {
665 	atomic_inc(&afs_outstanding_calls);
666 	queue_work(afs_wq, &afs_charge_preallocation_work);
667 }
668 
669 /*
670  * Grab the operation ID from an incoming cache manager call.  The socket
671  * buffer is discarded on error or if we don't yet have sufficient data.
672  */
673 static int afs_deliver_cm_op_id(struct afs_call *call)
674 {
675 	int ret;
676 
677 	_enter("{%zu}", call->offset);
678 
679 	ASSERTCMP(call->offset, <, 4);
680 
681 	/* the operation ID forms the first four bytes of the request data */
682 	ret = afs_extract_data(call, &call->tmp, 4, true);
683 	if (ret < 0)
684 		return ret;
685 
686 	call->operation_ID = ntohl(call->tmp);
687 	call->state = AFS_CALL_AWAIT_REQUEST;
688 	call->offset = 0;
689 
690 	/* ask the cache manager to route the call (it'll change the call type
691 	 * if successful) */
692 	if (!afs_cm_incoming_call(call))
693 		return -ENOTSUPP;
694 
695 	trace_afs_cb_call(call);
696 
697 	/* pass responsibility for the remainer of this message off to the
698 	 * cache manager op */
699 	return call->type->deliver(call);
700 }
701 
702 /*
703  * send an empty reply
704  */
705 void afs_send_empty_reply(struct afs_call *call)
706 {
707 	struct msghdr msg;
708 
709 	_enter("");
710 
711 	msg.msg_name		= NULL;
712 	msg.msg_namelen		= 0;
713 	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
714 	msg.msg_control		= NULL;
715 	msg.msg_controllen	= 0;
716 	msg.msg_flags		= 0;
717 
718 	call->state = AFS_CALL_AWAIT_ACK;
719 	switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0)) {
720 	case 0:
721 		_leave(" [replied]");
722 		return;
723 
724 	case -ENOMEM:
725 		_debug("oom");
726 		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
727 					RX_USER_ABORT, ENOMEM, "KOO");
728 	default:
729 		afs_end_call(call);
730 		_leave(" [error]");
731 		return;
732 	}
733 }
734 
735 /*
736  * send a simple reply
737  */
738 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
739 {
740 	struct msghdr msg;
741 	struct kvec iov[1];
742 	int n;
743 
744 	_enter("");
745 
746 	iov[0].iov_base		= (void *) buf;
747 	iov[0].iov_len		= len;
748 	msg.msg_name		= NULL;
749 	msg.msg_namelen		= 0;
750 	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
751 	msg.msg_control		= NULL;
752 	msg.msg_controllen	= 0;
753 	msg.msg_flags		= 0;
754 
755 	call->state = AFS_CALL_AWAIT_ACK;
756 	n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len);
757 	if (n >= 0) {
758 		/* Success */
759 		_leave(" [replied]");
760 		return;
761 	}
762 
763 	if (n == -ENOMEM) {
764 		_debug("oom");
765 		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
766 					RX_USER_ABORT, ENOMEM, "KOO");
767 	}
768 	afs_end_call(call);
769 	_leave(" [error]");
770 }
771 
772 /*
773  * Extract a piece of data from the received data socket buffers.
774  */
775 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
776 		     bool want_more)
777 {
778 	int ret;
779 
780 	_enter("{%s,%zu},,%zu,%d",
781 	       call->type->name, call->offset, count, want_more);
782 
783 	ASSERTCMP(call->offset, <=, count);
784 
785 	ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
786 				     buf, count, &call->offset,
787 				     want_more, &call->abort_code);
788 	trace_afs_recv_data(call, count, call->offset, want_more, ret);
789 	if (ret == 0 || ret == -EAGAIN)
790 		return ret;
791 
792 	if (ret == 1) {
793 		switch (call->state) {
794 		case AFS_CALL_AWAIT_REPLY:
795 			call->state = AFS_CALL_COMPLETE;
796 			break;
797 		case AFS_CALL_AWAIT_REQUEST:
798 			call->state = AFS_CALL_REPLYING;
799 			break;
800 		default:
801 			break;
802 		}
803 		return 0;
804 	}
805 
806 	if (ret == -ECONNABORTED)
807 		call->error = call->type->abort_to_error(call->abort_code);
808 	else
809 		call->error = ret;
810 	call->state = AFS_CALL_COMPLETE;
811 	return ret;
812 }
813